Transcribed Text
1.
The PVT behavior of a simple fluid obeys the equation of state
PV = RT  a P + bP

T
where a = 60000 cm³K/mol, b = 64 cm³/mol.
(a) (10) Calculate the enthalpy departure of this fluid at 350 K and 5 MPa.
(b) (10) Calculate the enthalpy of this fluid at 400 K and 10 MPa using a reference state of an
ideal gas at 300K and 0.1 MPa where HR18 = 0. For the purposes of the calculation, the
ideal gas heat capacity is CP = 14 R and is temperatureindependent.
2. A portion of the workbook PREOS.xlsx is shown below from the PROPS page.
(a) (5) What is the entropy at 150K and 1.5 MPa?
(b) (5) What equation number from the Elliott and Lira text is programmed into cell I9?
(c) (10) Suppose that the inlet to a throttle valve is 150 K and 1.5 MPa and the outlet is to be
0.05 MPa. Based on the state below, the outlet is likely to be two phases. Explain how
this is known. Explain how you would find the outlet temperature and quality using cell
references.
Microsoft Excel  Preos.xls

S
File Edit View Insert Format Tools Data Window
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EP
A
B
C
D
E
F
G
H
I
J
K
L
1
PengRobinson Equation of State (Pure Fluid)
Spreadsheet protected, but no password used.
2 Properties
Heat Capacity constants from Appendix
ideal gas
H°
3
Gas
Tc (K)
PC (MPa)
6
A
B
C
D
values
J/mol
J/mol
J/molK
4
Methane
190.6
4.604
0.011
19.25
5.21E02
1.20E05
1.13E08
4648.45
3417.98
43.754
5
6
Current State
Roots
Stable Root has a lower fugacity
7
T (K)
150
Z
V
fugacity
H
U
S
HH¹
UU°
8
P (MPa)
1.5
cm³/gmol
MPa
J/mol
J/mol
J/molK
J/mol
J/mol
J/molK
9
answers for three
0.707178 587.94781
1.162512
5585.72
6467.64
47.9619
955.419
590.241
4.25037
10
root region
0.2112416 175.62627
7425.67
7689.11
61.0281
2795.37
1811.71
17.3165
11
0.0493737
41.049328
0.895809
11848.2
11909.7
87.5448
7217.86
6032.34
43.8333
12
& for 1 root region
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13
fugratio
14
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14
4
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Instructions
h
PVT
Props
Ref State
Crit. Props Kig cp
4
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